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How to Nolog

Nolog - just listen to your logfiles.

nolog does

  • watch
  • shout
  • listen

to your logfiles.

or to put it another way

nolog matches patterns in logfiles to events, in real time. so stop thinking about logfiles as a big chunk of complicated data that lies around rotting somewhere on your server. logfiles are collections of events, time to treat them as such.

nolog is a new way to

  • parse
  • watch
  • think about

logfiles (done in node.js)

getting started

  >npm install nolog

great, you installed nolog.

now, in you script

  var $n = require('nolog');

you just loaded nolog into the variable $n.

WATCH a logfile

  $n('/path/to/logfile.log');

this logfile is not under supervision.

SHOUT

  $n('/path/to/my/logfile.log').shout('googlebot);

whenever nolog sees a 'googlebot' in your logfiles, it shouts 'googlebot'. one line after the other.

LISTEN

 $n('/path/to/my/logfile.log').shout('googlebot).on('googlebot', function(data){console.log(data);});

nolog listens if someone shouts 'googlebot' and does what it is told in the callback.

that is all you need to know. but if you want to know more, read along.

s, si and sin

lets start with si. siis short ofshoutIf`

  $n('/path/to/logfile.log').shoutIf('bot',/.*bot/i).on('bot', function(data){ console.log("it's a robot"); });
  //or if you do not want to write as much
  $n('/path/to/logfile.log').si('bot',/.*bot/i).on('bot', function(data){ ... });

shoutIf(eventname, pattern) shouts eventname if the pattern pattern is successfully encountered.

sin is short for shoutIfNot.

  $n('/path/to/logfile.log').shoutIfNot('human',/.*bot/i).on('human', function(data){ console.log("it's a human"); });
  //or the short way
  $n('/path/to/logfile.log').sin('human',/.*bot/i).on('human', function(data){ console.log("it's a human"); });

shoutIfNot(eventname, pattern) shouts eventname if the pattern pattern is not encountered. because a lot of time, you look for one thing, but you want the complete opposite.

so what about s. s is shot for shout and is a fluffy shortcut for shoutIf.

    $n('/path/to/logfile.log').shout('googlebot').on('googlebot', function(data){ console.log("it's google, again."); });
    //does the same stuff, as
    $n('/path/to/logfile.log').shoutIf('googlebot',/googlebot/i).on('googlebot', function(data){ console.log("it's google, again."); });

shout(eventname) shouts eventname if a case-insensitive match to eventname was found. because most of the time, if you are looking for a 'cat' you shout 'cat'.

listening

well, see http://nodejs.org/docs/v0.4.7/api/events.html#emitter.addListener

with all the above you are allready well equiped for everyday logfile listening. but there is even more.

patterns

patterns can be

  • regular expressions
  • strings
  • functions
  • booleans

for the regular expression stuff, see the examples above.

strings are treated as 'no fancy pancy stuff' regular expressions: "Test" matches "Test" and "(/%&/(%(&/$&%§$$%/&$&%/()%&89+++" matches "(/%&/(%(&/$&%§$$%/&$&%/()%&89+++" and nothing else (means: .*+?|()[]{}\ will be treated as 'normal' characters).

if you don't like RegExp you can pass functions as patterns. functions get the current line as argument, the return value gets passed to the listener callback method. see https://github.com/franzenzenhofer/nolog/blob/master/sample/uniqueip-functionpattern.js for a good example.

booleans - true will always match, false will never match.

notevents

ok, if you have come so far you are definitly really into this topic. (coming soon)